gtkaddpoi is a simple gtk interface for searching for an address and adding it as a POI (Point of Interest) in TangoGPS.
You can also insert the coordinates and a description for geocaching.
It uses Yahoo Maps API to find the coordinates of a given address and adds the POI to the TangoGPS database.
You can also delete a POI from TangoGPS database or export to KML or into Navit bookmark.